Electric heater.



BIE'SI AVAILABLE CQPY E. KEEN.

ELECTRIC HEATER.

APPLICATION FILED FEB. 29, ms.

Patented Mar. 27, 1917.

INVENTOR [L/OT KEEN ATTOR/IEYS' WITNESSES UNITED STATES PATENT OFFICE.

ELIOT KEEN, OF BROOKLYN, NEW YORK, ASSIGNOR TO THE ALADDIN LAMP CORPORA-TION, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

ELECTRIC HEATER.

Specification of Letters Patent.

Patented Mar. 27, 1917.

To all whom it may concern.

Be it known that I, ELIOT KEEN, a citizen of the United States, residingin the county of Kings, borough of Brooklyn, city and State of New York,have invented a new and useful Improvement in Electric Heaters, of whichthe following is a specification.

My invention relates to a portable electric heater for domestic,manufacturing and like uses, such as cooking, heating water, heatingglue pots and the like.

The object of my invention is to provide a simple, inexpensive, compactand durable heater of the class referred to, the parts of which are veryfew in number and require inexpensive materials, can be manufactured bya few very simple operations, and can be assembled very simply andquickly by cheap labor.

A further object of my invention is to provide an electric heater inwhich the support for the material to be heated, or for the receptaclecontaining such material, is also the support for the heat unit proper,the entire support comprising merely a single piece of stiff wireappropriately bent.

Still another object of my invention is to provide an electric heaterhaving a heat unit made of two identical supporting members, each ofwhich is independently wound with resistance wire; the necessaryelectrical connections for this resistance wire, including theconducting cord for connection to the operating circuit, are very simplymade on each member and in such a way that when the members are unitedtogether the connections are not only concealed but are locked so thatthey may not be strained or pulled out.

Other objects of the invention will appear as the specificationproceeds.

The invention resides in certain features of construction as will behereinafter described and more specifically set forth in the claims.

Essentially my invention comprises a base which carries a stiff wirehaving a substantial part of its length bent in zigzag fashion in itsown plane so as to constitute a support for the receptacle or materialto be heated and its two ends bent in another plane parallel with butbelow the supporting plane just mentioned. The heat unit proper, whenassembled, comprises a pair of parallel hollow bobbins wound withresistance wire and fixed to a common connecting bar or base from whichgoes the conducting cord. This pair of bobbins is slipped over the twoends of the supporting wire and fastened immovably with respect thereto.In making the bends of the wire support, as above referred to, fourdownwardly extended loops are provided which are engaged with suitableretaining members attached to the base.

My invention will be better understood by referring to the accompanyingdrawing in which Figure 1 represents a plan view of a preferred form ofelectric heater according to my invention; Fig. 2 represents a sideelevation of Fig. 1; and Figs. 3 to 6 inclusive, represent views, on ascale double that of Figs. 1 and 2; Fig. 3 being a horizontal sectionalong the line 3-3 of Fig. 2; Fig. 4: being a transverse section alongthe line 44.- of Fig. 3; Fig. 5 being a side elevation of the completedheat unit; and Fig. 6 a transverse section taken along the line 6-6 ofFig. 1.

In the drawing a substantially rectangular base 1 is formed, preferablyby stamping, from sheet metal; at each corner this base is provided witha strip like extension 2 having rcentrant slots 3 on each side thereof.These strips 2 are bent downwardly, inwardly and upwardly so as toconstitute feet by means of which the base is supported spaced from thetable. The ends of the feet do not completely close against the underside of the base so that each foot also con stitutes a centrally turnedhook.

A suitable length of stiff wire 4 is bent, in zigzag fashion, back andforth in its own plane so as to constitute a support 5 for thereceptacle or material to be heated. In thus bending this wire 4,downwardly and outwardly extended loops 6 are formed and these loops,being pressed centrally against the resiliency of the material may beentered into slots 3, slipping under the feet 2, and then permitted toslip into the hooks which said feet constitute. In this way the Iiupportis simply and strongly locked to the ase.

The ends of wire 4 are bent downwardly and then into a plane parallel tothe plane of the support 5 and lying symmetrically on each side of thecenter line of the heater.

The heat unit pro or comprises two identical porcelain bloc s 7. Each ofthese 110 blocks consists of a connecting bar or base 8 having at oneside thereof a bobbin 9 provided with a spiral groove 10 in which islaid the resistance wire. The bobbin 9 is ofiset with reference to theblock 8 so that its central longitudinal section lies in the same planeas the top of the block.

Two holes 11, 11 are pierced through each bobbin adjacent to the ends ofthe spiral groove. in winding the wire 12 upon the bobbin the one end isfirst inserted through hole 11 and then bent sharply back upon itselfagainst the outside of the bobbin, whereby this end becomes firmlyanchored. The other end of the wire is similarly passed through hole 11and similarly bent. The outer ends of the two wires are connectedtogether (Figs. 1 and 6) by means of a thin walled tubular connector 13having lateral openings 1 L near one end. This tube is just long enoughto fit between the ends of the bobbins and the ends of the two wires arepassed through holes 1 1. With a suitable tool the connector 13 is thencrushed at two points 15 so as to firmly grip the two ends of the wire.

The block 8 is provided with a U-shaped recess 16, of semicircularsection, having its ends opening symmetrically on each side of thecenter. Each slot has a pair of lateral recesses 16 opening therein. Atubular connector 17 having a pair of set screws 18-48 passing throughthe walls thereof is fitted to each leg of slot 16. The inner end ofeach resistance wire 12 is connected to one end of the connector whilethe other end of each connector receives a terminal of the con ductingcord 19. The two porcelain blocks 7 are then placed one over the other,with slots 16 in registry, and fastened together by screws 20 and nuts21. Set screws 18, 18 will then be clamped in the recesses 16; in thisway the tubular connectors 17 are fixedly held and no strain in theconducting cord can be transmitted to the resistance wire 12.

When thus assembled the terminals of the resistance wire as also of theconducting cord of the heat unit are not only perfectly insulated butalso firmly anchored. Any strain or pull upon the conducting cord 19 isnot likely to be transmitted to the pointof con tact between set screw18 and the end of the conducting cord, because of the fact that eachseparate conductor of the conducting cord, as it passes from theconnector 17, leaves the connecting bar by a central opening 22 so thatit must be sharply bent through 90 around a corner of the porcelain andthis corner will, therefore, prevent any slip of the cord and take upall strain.

The screws 20 are prolonged downwardly Copies of this patent may beobtained for five cents each, by addressing the and each is providedwith a shoulder and a reduced threaded portion which is passed through asuitably located hole in base 1. Nuts 23 are then applied to the reducedportions on the lower side of the base thus locking the heat unit properand the base firmly together.

Modifications of the structure herein disclosed may be made within thespirit of the invention as defined by the following claims.

1 claim:

1. An electric heater comprising a wire having portions bent in twoparallel planes, a heat unit attached to one of said portions andentirely to one side of the plane of the other portion and a support forsaid wire.

2. An electric heater comprising a wire having portions bent in twoparallel planes arranged one below the other, a heat unit lying entirelybelow the upper plane and a tached to the portion having the lowerplane, the heat unit having an air space on its under side, and asupport for said wire.

3. An electric heater comprising a wire one part of which has aplurality of bends in a single plane so as to constitute a support forthat which is to be heated while another part lies in a plane parallelto but beneath the first plane, and a heat unit supported by said secondpart entirely outside the plane of the first part, other parts of thewire being bent downwardly so as to constitute feet.

at. An electric heater comprising a wire having portions bent to and froin one plane to constitute a support for that which is to be heated,other portions bent downwardly as loops, and parallel end portions lyingin a plane beneath the first named plane, a heat unit having parallelhollow bobbins into which said ends project, a base beneath the heatunit with which the bottoms of the loops are engaged, and means forfastening the heat unit and the base together.

5. An electric heater comprising a base, a pair of spaced parallelsupporting wires carried by said base and a heat unit comprisingparallel hollow bobbins wound with conducting wire and fixed to one sideof a connecting block the terminals of said conducting wire passing intothe connecting block and being there joined to cord terminals and thecord being anchored in the block, the hollow bobbins being threaded uponthe supporting wires and held in a predetermined position thereupon.

In testimony whereof 11 have hereunto set my hand.

ELIOT KEEN.

Witnesses:

Emma G. "WILLYOUNG, Gr. V. RAsMUssnN.

Commissioner of Patents,

Washington, D. G.

